With Arduino 1.8.8 Hourly Build 2018/11/30 12:33 on a Windows 10 box, my Windows file content searches have not revealed where AVR_ARCH is defined, nor what its expected values would be. It does not appear on any command lines in the verbose output from the build process either.
When I compile, I can see the value is 5. I don’t know how the IDE would know what hardware platform I purchased (which happens to be an OSEPP UNO R3 Plus) without me putting something in the likes of platform.local.text. A couple hours of web searching has thus far turned up nothing relevant.
I thought it might somehow be ‘manufactured’ through token pasting, but that theory has not panned out either.
Thanks in advance for your thoughts.